Merging Issue

As shown in the figure below, I would like to merge Table 1 and Table 2 using common key IDs: card_nbr and transaction_name. However, I found out that the transaction names in table 2 are truncated.

Table 1

Table 2

card_nbr

transaction_name

card_nbr

transaction_name

8000

Harvey Norman 12M: 0/12

8000

Harvey Norman 12M

7000

Ikea 36M: 0/12

7000

Ikea 36M

How do I truncate the transaction name in Table 1 to match the data in Table 2? I have checked the rest of the data and only these installment transactions would have the symbol ":" followed by e.g: 0/12, 3/12. etc. I would like to remove anything from the symbol ":" onwards from Table 1.